One of the happiest moments of this lost summer for the New York Mets came last week, when Jeff McNeil made his major-league debut as a pinch-hitter in the eighth inning of Tuesday’s 6-3 win over the San Diego Padres and lined a single to center field.

McNeil, a 12th-round draft pick in 2013, grinded his way through the farm system to get to the majors, but even his success in making it to the top could not be a universally feel-good story because of the way the Mets handled him, claiming publicly through manager Mickey Callaway that he was “purely a second baseman”. McNeil was not that.

“I’ve played a lot of third base in the minors,” McNeil told the Guardian. “And I’ve played a lot of second base. I played a lot of outfield in college. I’m comfortable there, just haven’t gotten many reps in the minors. But anywhere they put me, I’ll feel pretty comfortable.”

Instead of using an injury to regular third baseman Todd Frazier to get a look at McNeil, their 19th-ranked prospect by MLB Pipeline, the Mets handed starts at the hot corner to 35-year-old Jose Reyes, one of the worst players in the majors this year, and to 37-year-old washed-up former MVP Jose Bautista, an outfielder for almost his entire career.

The Mets lost 92 games last year, and decided to try to return to relevance by making a splash in free agency with Frazier, Jay Bruce, Adrian Gonzalez, Anthony Swarzak, Jose Lobaton and the controversial re-signing of Reyes. That activity, combined with hopes for better injury luck, had most projection systems tapping the Mets for somewhere in the neighborhood of 80 wins in 2018, while having done nothing to help themselves on a long-term basis. It will now take a miracle for the Mets to finish this season anywhere near the .500 mark.

“It seems like they always build for respectability,” said Roger Cormier, one of the hosts of the Mets podcast Good Fundies. “If the Mets finished 79-83, like they did in 2014, every year, that would be acceptable to most people, because if you finish 79-83, that means in the offseason, it would look like you were trying for 85-77, and that would be acceptable – second wild card, maybe first wild card, in the National League! You save money doing that, but then you’re also stuck in the middle, where you’re not doing as well as the people who purposely tank.”

The Mets’ approach almost feels like they are trying to be Everton, which holds the distinction of never having been relegated from, but also never having won, the English Premier League. The problem is that there is no relegation in baseball and probably won’t be for several decades at least, and thus there is no real penalty for tanking other than losing games.

It’s admirable for the Mets to at least go into seasons with hopes that their 79-ish win roster can win 85-ish games and contend for a playoff spot, but when that doesn’t happen, Major League Baseball not having a relegation system should encourage them to take strides to improve themselves for the long term by trading established veterans for prospects. Instead, the Mets wind up pursuing salary relief, and have been widely panned for the return they got when they sent Jeurys Familia, a free agent at the end of the season, to the Oakland A’s. In that deal, the Mets picked up 26-year-old relief pitcher Bobby Wahl, who strikes out a ton of hitters but also walks a bunch, and Class-AA third baseman Will Toffey, who entered the organization as the Mets’ No 24 prospect.

The San Diego Padres’ 2016 trade for Fernando Tatis Jr might have limited their ability to contend in the short term, but they may well have landed their shortstop of the future. Photograph: Rob Tringali/MLB Photos via Getty Images

Toffey is the highest-ranked Mets prospect who did not enter professional baseball with the Mets. On the other hand, after their failed spending spree to try to become contenders before the 2015 season, the Padres took a different approach.

By eating $31m of the $58m that was still owed to James Shields when they traded him to the White Sox in 2016, the Padres were able to land Fernando Tatis Jr, highly regarded then, and now the second-best prospect in all of baseball. This month, the Padres traded relief pitchers Brad Hand and Adam Cimber to Cleveland, getting back Francisco Mejia, the game’s top catching prospect. Pitcher Chris Paddack, the Padres’ No 5 prospect, came over in a 2016 trade with the Marlins for journeyman reliever Fernando Rodney. San Diego’s eighth-ranked prospect, lefthander Logan Allen, came from the Red Sox in the trade for dominant closer Craig Kimbrel, as did the Padres’ current starting center fielder, Manuel Margot, utility infielder Carlos Asuaje, and minor league shortstop Javy Guerra, who has not hit much, but is in Class-AAA ball at age 22 and has had a brief major-league callup.

The Padres have eight prospects in MLB Pipeline’s top 100, including five in the top 50. The Mets have four top-100 prospects, but none ranked above No 60. That’s not a guarantee of future success, but unlike with New York, you can at least see what the plan is for San Diego.

“They’ve won two pennants in, now 50 seasons of baseball, so I think there’s an acceptance from the fanbase that nothing else has worked, so let’s give this a shot,” Padres broadcaster Jesse Agler said. “For the Padres to fully commit to this minor league system, and the amount of money they put into international signings a couple of years ago, it’s a legitimate commitment to build this thing from the ground up.”

The Padres lost one fewer game than the Mets did last year, and the race between the last-place teams in the National League East and West (indeed, the two worst in the senior circuit) would be a hot one if MLB had a relegation system. Since there isn’t one, the Padres will do what they can before Tuesday’s trade deadline to turn the expiring contracts of players like Tyson Ross into prospects who can help build San Diego’s future. On the field, the Padres are prioritizing experience for the younger players so they won’t be cowed when the team is ready to contend.

“I never feel a need to incentivize behavior to get done what we want done,” Padres manager Andy Green said. “I think these guys are responsive to what we ask because they know what’s out in front of them. A lot of these guys are competing for the opportunity to be part of a winning culture in the future, and to do that, they have to show certain attributes, and these guys are very cognizant of what we want. I’ve got a great group of guys that want to play well, listen to coaches, and do what we ask.”

As for the Mets, the New York Post reported on Thursday that they are likely to hold on to Bautista, because of Yoenis Cespedes’ season-ending surgery, as if keeping a 37-year-old outfielder around for two months somehow makes better sense than at least seeing what some younger players can do.

What the Padres are doing can be considered tanking a season or three. The Mets’ inability or unwillingness to recognize that there’s no meaningful difference between an 85-loss team and a 105-loss team can be considered tanking a franchise, as year after year they try to avoid being relegated from a league that does not have relegation.